Table 2. Determinants of LT4 overtreatment and undertreatment (n = 557).
| Status | Determinant | OR | [95% CI] | p |
| Overtreated | Age 40–49 years (vs. 30–39 years) | 0.89 | [0.34; 2.35] | 0.810 |
| Age 50–59 years (vs. 30–39 years) | 1.87 | [0.73; 4.75] | 0.189 | |
| Age 60–69 years (vs. 30–39 years) | 2.73 | [0.96; 7.74] | 0.060 | |
| Age ≥ 70 years (vs. 30–39 years) | 4.05 | 1.20; 13.72] | 0.025 | |
| Sex (men vs. women) | 0.84 | [0.43; 1.65] | 0.616 | |
| Education (low vs. middle) | 0.29 | [0.03; 2.52] | 0.262 | |
| Education (high vs. middle) | 1.22 | [0.74; 2.00] | 0.438 | |
| Smoking (former vs. never) | 0.61 | [0.36; 1.04] | 0.068 | |
| Smoking (current vs. never) | 1.42 | [0.69; 2.92] | 0.337 | |
| BMI (kg/m2, increase per unit) | 0.95 | [0.90; 1.01] | 0.077 | |
| Diabetes (yes vs. no) | 0.63 | [0.21; 1.94] | 0.420 | |
| Hypertension (yes vs. no) | 0.79 | [0.44; 1.41] | 0.422 | |
| CVD (yes vs. no) | 0.51 | [0.19; 1.37] | 0.182 | |
| CKD (yes vs. no) | 1.50 | [0.53; 4.24] | 0.444 | |
| Iodine supplementation (yes vs. no) | 1.11 | [0.63; 1.96] | 0.725 | |
| Polypharmacy (yes vs. no) | 1.07 | [0.60; 1.92] | 0.812 | |
| LT4 dose (per 25 µg increase) | 1.02 | [1.02; 1.03] | < 0.001 | |
| LT4 intake 13–36 months (vs. 0–12 months) | 0.59 | [0.18; 1.96] | 0.389 | |
| LT4 intake > 36 months (vs. 0–12 months) | 0.50 | [0.18; 1.42] | 0.192 | |
| Global cognition (z-score, per SD) | 1.23 | [0.72; 2.09] | 0.445 | |
| Undertreated | Age 40–49 years (vs. 30–39 years) | 0.64 | [0.12; 3.53] | 0.607 |
| Age 50–59 years (vs. 30–39 years) | 1.58 | [0.34; 7.41] | 0.560 | |
| Age 60–69 years (vs. 30–39 years) | 1.42 | [0.23; 8.76] | 0.703 | |
| Age ≥ 70 years (vs. 30–39 years) | 1.72 | [0.21; 14.27] | 0.617 | |
| Sex (men vs. women) | 1.42 | [0.47; 4.32] | 0.539 | |
| Education (low vs. middle) | – | – | – | |
| Education (high vs. middle) | 0.85 | [0.35; 2.09] | 0.725 | |
| Smoking (former vs. never) | 0.78 | [0.29; 2.09] | 0.623 | |
| Smoking (current vs. never) | 1.93 | [0.56; 6.64] | 0.299 | |
| BMI (kg/m2, increase per unit) | 0.96 | [0.87; 1.06] | 0.418 | |
| Diabetes (yes vs. no) | 1.16 | [0.20; 6.63] | 0.867 | |
| Hypertension (yes vs. no) | 0.97 | [0.33; 2.81] | 0.951 | |
| CVD (yes vs. no) | 3.04 | [0.80; 11.56] | 0.103 | |
| CKD (yes vs. no) | 2.08 | [0.42; 10.39] | 0.370 | |
| Iodine supplementation (yes vs. no) | 0.27 | [0.06; 1.27] | 0.097 | |
| Polypharmacy (yes vs. no) | 0.67 | [0.21; 2.13] | 0.494 | |
| LT4 dose (per 25 µg increase) | 1.02 | [1.00; 1.03] | 0.017 | |
| LT4 intake 13–36 months (vs. 0–12 months) | 0.26 | [0.03; 2.23] | 0.220 | |
| LT4 intake > 36 months (vs. 0–12 months) | 0.42 | [0.08; 2.23] | 0.312 | |
| Global cognition (z-score, per SD) | 1.37 | [0.55; 3.46] | 0.499 |
The sample size is based on persons with complete data on all determinants.
BMI, Body mass index; CI, confidence interval; CKD, chronic kidney disease; CVD, cardiovascular disease; LT4, levothyroxine; n, number of participants; OR, odds ratio; SD, standard deviation; vs., versus